1. Technical Field
The present invention relates to an electronic timepiece, and relates more particularly to an electronic timepiece that can receive radio signals.
2. Related Art
Electronic timepieces having a timekeeping unit that keeps and displays time, and a heavy load system that has high power consumption compared with the timekeeping unit, are known from the literature. The electronic timepiece disclosed in Japanese Unexamined Patent Appl. Pub. JP-A-2007-101233, for example, has an electronic clock circuit as the timekeeping unit, and a keyless entry circuit as the heavy load system. In addition to a timekeeping unit, other electronic timepieces have a receiver circuit to receive radio signals such as time standard signals or satellite signals transmitted from GPS (Global Positioning System) satellites as the heavy load system.
In order to drive the heavy load system and timekeeping unit stably, an electronic timepiece with a heavy load system preferably uses separate power supplies to drive the heavy load system and timekeeping unit. More particularly, the receiver unit that receives radio signals is preferably driven using a stable voltage in order to improve reception sensitivity.
The electronic timepiece disclosed in JP-A-2007-101233 therefore has two batteries, a battery for the clock control circuit and a battery for the keyless entry circuit.
However, providing two batteries in an electronic timepiece increases the size of the electronic timepiece.